Abstract P22: Role of Specific Medications as Determinants of Pulseless Electrical Activity
Introduction: We have previously identified specific clinical determinants of pulseless electrical activity versus ventricular fibrillation. With increasing age and widespread use of medications with cardiac effects, drugs are potential determinants of terminal arrhythmias but systematic studies are lacking.
Methods: Cases of sudden cardiac arrest (SCA) (age ≥18 yrs) that underwent resuscitation by first responders in the northwestern US (2002–2007) were evaluated. Comparisons of presenting rhythm and medication use were conducted using Pearson chi-square tests. Information on use of medications was obtained from physician dictations prior to and closest to the arrest, or from information obtained by EMS or the medical examiner at the time of arrest.
Results: Cases with resuscitation attempted (n=1277) (mean age 65±16, 66.7% male) were included in the study. Ventricular fibrillation or tachycardia (VF/VT) was observed in 48.0% of cases, pulseless electrical activity (PEA) in 26.4%, and asystole in 25.6%. Cases with VF/VT were younger and more likely to be male compared to PEA cases (p≤0.0002). The use of ACE inhibitors was more common among cases presenting with VF/VT (37%) compared to PEA (26%) (p=0.003). Similarly, aldosterone antagonists were more likely to be associated with VF/VT (5%) compared to PEA (1%) (p=0.01). Antipsychotic medications (9% vs. 2%, p<0.0001) and QT prolonging drugs (39% vs. 28%, p=0.001) were more associated with PEA vs. VF/VT. Antidepressant medications were somewhat more common among PEA cases vs. VF/VT (25% vs. 19%, p=0.06). There were no differences in the use of beta blockers, Angiotensin Receptor Blockers, and diuretics by presenting rhythm (p≥0.30). In a logistic regression model adjusting for age, gender, response time and comorbidities, antipsychotic medication was a strong predictor of PEA [OR 2.90; 95% CI (1.24 – 6.78)].
Conclusions: Commonly used medications including beta blockers, ACE inhibitors, diuretics and antidepressants were not associated with the type of terminal arrhythmia after adjusting for comorbidities and other medication use. However, use of antipsychotic agents increased likelihood of PEA by 3 fold, an association that merits further evaluation.